// swiftlint:disable file_length

import SwiftUI

// swiftlint:disable:next type_body_length
struct GenericListView<T: Identifiable & Hashable & GenericItem>: View {
  @EnvironmentObject private var settings: SettingsManager
  @EnvironmentObject private var manager: BooruManager
  @Binding var selectedTab: Int
  @State private var searchText: String = ""
  @State private var isShowingRemoveAllConfirmation = false
  @Binding var isPresented: Bool
  @State private var isNewCollectionAlertPresented = false
  @State private var newCollectionName = ""
  @State private var itemPendingCollectionAssignment: UUID?
  @State private var isCollectionErrorAlertPresented = false
  @State private var selectedCollectionOption: CollectionPickerOption = .all
  @State private var sort: SettingsBookmarkSort = .dateAdded
  @State private var isCollectionPickerPresented = false
  @State private var isProviderPickerPresented = false
  @State private var selectedProvider: BooruProvider?
  let allowBookmarking: Bool
  let title: String
  let emptyMessage: String
  let emptyIcon: String
  let emptyDescription: String
  let removeAllMessage: String
  let removeAllButtonText: String
  let items: [T]
  let removeAction: (IndexSet) -> Void
  let removeActionUUID: (UUID) -> Void
  let removeAllAction: () -> Void

  var filteredItems: [T] {
    items.filter { item in
      let matchesFolder: Bool = {
        switch selectedCollectionOption {
        case .all:
          return true

        case .uncategorized:
          return item.folder == nil

        case .folder(let folderId):
          return item.folder == folderId
        }
      }()
      let matchesSearch =
        searchText.isEmpty
        || item.tags
          .joined(separator: " ")
          .lowercased()
          .contains(searchText.lowercased())
      let matchesProvider =
        selectedProvider == nil
        || item.provider == selectedProvider

      return matchesFolder && matchesSearch && matchesProvider
    }
  }

  var sortedFilteredItems: [T] {
    if allowBookmarking {
      return filteredItems.sorted { $0.date > $1.date }
    }

    return filteredItems.sorted { (lhs: T, rhs: T) in
      switch sort {
      case .dateAdded:
        return lhs.date > rhs.date

      case .lastVisited:
        return lhs.lastVisit > rhs.lastVisit

      case .visitCount:
        return lhs.visitedCount > rhs.visitedCount
      }
    }
  }

  @ViewBuilder private var listContent: some View {
    List {
      if filteredItems.isEmpty && (!searchText.isEmpty || !(selectedCollectionOption == .all)) {
        Text("No matching items found")
          .foregroundColor(.secondary)
      }

      ForEach(sortedFilteredItems, id: \.id) { item in
        itemButtonContent(item: item)
      }
      .onDelete(perform: removeAction)
    }
  }

  private func isProviderBookmarked(_ provider: BooruProvider) -> Bool {
    settings.bookmarks.contains { $0.provider == provider }
  }

  private func isCollectionPopulated(_ folder: UUID?) -> Bool {
    settings.bookmarks.contains { $0.folder == folder }
  }

  var body: some View {
    NavigationStack {
      VStack(spacing: 0) {
        if items.isEmpty {
          ContentUnavailableView(
            emptyMessage,
            systemImage: emptyIcon,
            description: Text(emptyDescription)
          )
        } else {
          #if os(macOS)
            if !settings.folders.isEmpty && !allowBookmarking {
              Picker("Sort", selection: $sort) {
                ForEach(SettingsBookmarkSort.allCases, id: \.rawValue) { sortMode in
                  Text(sortMode.rawValue).tag(sortMode)
                }
              }
              .padding()
              .pickerStyle(.menu)

              Picker("Collection", selection: $selectedCollectionOption) {
                Text(CollectionPickerOption.all.name(settings: settings))
                  .tag(CollectionPickerOption.all)

                if items.contains(where: { $0.folder == nil }) {
                  Text(CollectionPickerOption.uncategorized.name(settings: settings))
                    .tag(CollectionPickerOption.uncategorized)
                }

                ForEach(settings.folders.filter { $0.topLevelName == nil }, id: \.id) { folder in
                  Text(folder.name).tag(CollectionPickerOption.folder(folder.id))
                }

                let topLevelFolders = settings.folders
                  .reduce(into: [String: [SettingsFolder]]()) { result, folder in
                    guard let topLevelName = folder.topLevelName else { return }

                    result[topLevelName, default: []].append(folder)
                  }

                ForEach(topLevelFolders.keys.sorted(), id: \.self) { topLevelName in
                  Menu {
                    ForEach(topLevelFolders[topLevelName] ?? [], id: \.id) { folder in
                      Button(action: {
                        selectedCollectionOption = .folder(folder.id)
                      }) {
                        Text(folder.shortName)
                      }
                    }
                  } label: {
                    Text(topLevelName)
                  }
                }
              }
              .padding(.bottom)
              .padding(.horizontal)
              .pickerStyle(.menu)

              Picker("Provider", selection: $selectedProvider) {
                Text("All").tag(nil as BooruProvider?)

                ForEach(BooruProvider.allCases, id: \.rawValue) { provider in
                  if isProviderBookmarked(provider) {
                    Text(provider.rawValue).tag(provider)
                  }
                }
              }
              .padding(.bottom)
              .padding(.horizontal)
              .pickerStyle(.menu)
            }
          #endif

          if allowBookmarking {
            listContent
              #if os(iOS)
                .searchable(text: $searchText, placement: .navigationBarDrawer)
              #endif
          } else {
            listContent.searchable(text: $searchText)
          }
        }
      }
    }
    .navigationTitle(title)
    .refreshable { settings.syncFromCloud() }
    .toolbar {
      #if os(macOS)
        ToolbarItem {
          Button(action: {
            settings.syncFromCloud()
          }) {
            Label("Refresh", systemImage: "arrow.clockwise")
          }
        }
      #endif

      #if os(macOS)
        ToolbarItem {
          Button(
            role: .destructive,
            action: {
              isShowingRemoveAllConfirmation = true
            }
          ) {
            Label("Remove All", systemImage: "trash")
          }
        }
      #endif

      #if os(iOS)
        ToolbarItemGroup(placement: .secondaryAction) {
          if !allowBookmarking {
            Menu {
              Picker("Sort By", selection: $sort) {
                ForEach(SettingsBookmarkSort.allCases, id: \.rawValue) { sortMode in
                  Text(sortMode.rawValue).tag(sortMode)
                }
              }
            } label: {
              Label("Sort By", systemImage: "arrow.up.arrow.down")
            }

            Menu {
              Picker("Collection", selection: $selectedCollectionOption) {
                Text(CollectionPickerOption.all.name(settings: settings))
                  .tag(CollectionPickerOption.all)

                if items.contains(where: { $0.folder == nil }) {
                  Text(CollectionPickerOption.uncategorized.name(settings: settings))
                    .tag(CollectionPickerOption.uncategorized)
                }

                ForEach(settings.folders.filter { $0.topLevelName == nil }, id: \.id) { folder in
                  Text(folder.name).tag(CollectionPickerOption.folder(folder.id))
                }

                let topLevelFolders = settings.folders
                  .reduce(into: [String: [SettingsFolder]]()) { result, folder in
                    guard let topLevelName = folder.topLevelName else { return }

                    result[topLevelName, default: []].append(folder)
                  }

                ForEach(topLevelFolders.keys.sorted(), id: \.self) { topLevelName in
                  Menu {
                    ForEach(topLevelFolders[topLevelName] ?? [], id: \.id) { folder in
                      Button(action: {
                        selectedCollectionOption = .folder(folder.id)
                      }) {
                        Text(folder.shortName)
                      }
                    }
                  } label: {
                    Text(topLevelName)
                  }
                }
              }
            } label: {
              Label("Collection", systemImage: "folder")
            }

            Menu {
              Picker("Provider", selection: $selectedProvider) {
                Text("All").tag(nil as BooruProvider?)

                ForEach(BooruProvider.allCases, id: \.rawValue) { provider in
                  Text(provider.rawValue)
                    .tag(provider)
                    .selectionDisabled(!isProviderBookmarked(provider))
                }
              }
            } label: {
              Label("Provider", systemImage: "globe")
            }

            Button(
              role: .destructive,
              action: {
                isShowingRemoveAllConfirmation = true
              }
            ) {
              Label("Delete All", systemImage: "trash")
            }
          }
        }
      #endif
    }
    .alert(
      removeAllMessage,
      isPresented: $isShowingRemoveAllConfirmation
    ) {
      Button(removeAllButtonText) {
        removeAllAction()
      }

      Button("Cancel", role: .cancel) { () }
    }
    .collectionAlerts(
      isNewCollectionAlertPresented: $isNewCollectionAlertPresented,
      newCollectionName: $newCollectionName,
      isCollectionErrorAlertPresented: $isCollectionErrorAlertPresented
    ) { newCollectionName in
      let newFolder = SettingsFolder(name: newCollectionName)

      settings.folders.append(newFolder)

      if let id = itemPendingCollectionAssignment {
        settings.updateBookmarkFolder(withID: id, folder: newFolder.id)
      }

      itemPendingCollectionAssignment = nil
    }
  }

  func itemButtonContent(item: T) -> some View {
    Button(action: {
      let previousProvider = settings.preferredBooru

      settings.preferredBooru = item.provider
      manager.searchText = item.tags.joined(separator: " ")
      selectedTab = 0

      isPresented.toggle()

      if previousProvider == settings.preferredBooru {
        let localManager = manager
        let localSettings = settings

        Task(priority: .userInitiated) {
          await localManager.performSearch(settings: localSettings)
        }
      }

      if !allowBookmarking {
        settings.incrementBookmarkVisitCount(withID: item.id)
        settings.updateBookmarkLastVisit(withID: item.id)
      }
    }) {
      GenericItemView(
        item: item,
        removeAction: removeActionUUID
      )
    }
    .contextMenu {
      Button(action: {
        manager.searchText += " \(item.tags.joined(separator: " "))"
        manager.selectedPost = nil

        let localManager = manager
        let localSettings = settings

        isPresented.toggle()

        Task(priority: .userInitiated) {
          await localManager.performSearch(settings: localSettings)
        }
      }) {
        Label("Add to Search", systemImage: "plus")
      }

      if allowBookmarking {
        let isBookmarked = settings.bookmarks.contains { $0.tags == item.tags }

        Button(action: {
          if isBookmarked {
            settings.removeBookmark(withTags: item.tags)
          } else {
            settings.addBookmark(provider: settings.preferredBooru, tags: item.tags)
          }
        }) {
          if isBookmarked {
            Label("Remove Bookmark", systemImage: "bookmark.fill")
          } else {
            Label("Bookmark Tag\(item.tags.count == 1 ? "" : "s")", systemImage: "bookmark")
          }
        }
      }

      Menu {
        ForEach(settings.folders.filter { $0.topLevelName == nil }, id: \.id) { folder in
          Button(action: {
            settings.updateBookmarkFolder(withID: item.id, folder: folder.id)
          }) {
            Label(folder.name, systemImage: "folder")
          }
          .disabled(item.folder == folder.id)
        }

        let topLevelFolders = settings.folders
          .reduce(into: [String: [SettingsFolder]]()) { result, folder in
            guard let topLevelName = folder.topLevelName else { return }

            result[topLevelName, default: []].append(folder)
          }

        ForEach(topLevelFolders.keys.sorted(), id: \.self) { topLevelName in
          Menu {
            ForEach(topLevelFolders[topLevelName] ?? [], id: \.id) { folder in
              Button(action: {
                settings.updateBookmarkFolder(withID: item.id, folder: folder.id)
              }) {
                Text(folder.shortName)
              }
              .disabled(item.folder == folder.id)
            }
          } label: {
            Text(topLevelName)
          }
        }

        Button(action: {
          itemPendingCollectionAssignment = item.id
          isNewCollectionAlertPresented = true
        }) {
          Label("New Collection", systemImage: "plus")
        }
      } label: {
        Label("\(item.folder != nil ? "Move" : "Add") to Collection", systemImage: "folder")
      }

      if item.folder != nil {
        Button(action: {
          settings.updateBookmarkFolder(withID: item.id, folder: nil)
        }) {
          Label("Remove from Collection", systemImage: "folder.badge.minus")
        }
      }

      Button {
        removeActionUUID(item.id)
      } label: {
        Label("Delete", systemImage: "trash")
      }
    }
    #if os(macOS)
      .buttonStyle(.plain)
    #endif
  }
}